This application claims priority under 35 U.S.C. xc2xa7119 from a Japanese Patent Application No. 9-369501 filed on Dec. 26, 1997, which is incorporated herein by reference for all purposes.
The present invention relates to a molded article laminated with fabric which is prepared by adhering a fabric made up of highly heat resisting fibers to the surface of a molding produced from a thermoplastic resin and to a method for reprocessing the molded article laminated with fabric.
Plastic moldings, which are used in such applications as inner walls, partitions and doors of buildings, and head rests, arm rests and solid portions of console boxes of automobiles and which are molded articles laminated with fabric, are described in Japanese Patent Application Publication (JP-B) No. 63-51,088.
In the case of the molded articles laminated with fabric described in JP-B No. 63-51,088, as will be seen in FIG. 1, a fiber sheet is present in part of the mold flash when the molding is prepared. Generally, mold flashes which contain no fiber sheet are reprocessed without any treatment. The mold flashes and defective moldings which contain a fiber sheet are actually discarded without being reused. This is because the residual fiber sheet brings about the problem that the difference in bulk density between fibrous portions and the resinous portions causes nonuniformity in the charging amount to an extruder thereby making the extruded amount unstable. In addition, the reuse of the mold flashes containing a fiber sheet brings about the problem that fibrous lumps remain on the surface of the moldings obtained thereby impairing the appearance and significantly reducing the physical strength of the moldings.
Accordingly, for the preparation of a mold article laminated with fabric, the mold structure needs to be designed so that the amount of mold flashes is minimized. Despite such precaution in designing, however, fiber sheets needs to be carefully removed manually if the mold flashes containing the fiber sheets are reused.
In view of the actual situation where a large amount of molded articles laminated with fabric are widely used in the field of automobile industry, construction industry and the like, it is extremely difficult to manually remove the fiber sheets from the mold flashes in terms of productivity. Therefore, it is an inevitable consequence that the mold flashes are forced to be discarded in the face of the fact that the recycling of plastics is strongly encouraged.
Accordingly, an object of the present invention is to provide a method not only for reprocessing the mold flashes at the time of the preparation of molded articles laminated with fabric but also for reprocessing the defective molded articles laminated with fabric which come from the production line and are destined to be discarded.
Another object of the present invention is to provide a method which makes it possible to prevent the impairment of the physical properties and appearance of the moldings prepared by reusing the resinous material containing the fiber sheets and which enables accurate control of the parameters, such as wall thickness of the moldings, in the forming process.
The molded article laminated with fabric according to the present invention is a molding which is made from a thermoplastic resin (A) and has a fabric, made up of fibers of a highly heat resisting thermoplastic resin (B), adhered to the surface thereof, wherein the thermoplastic resin (A) of the molding contains the highly heat resisting thermoplastic resin (B) constituting the fibers and wherein the highly heat resisting thermoplastic resin (B) is present as minute particles in the thermoplastic resin (A). In the molded article laminated with fabric of the present invention, it is desirable that the content of the highly heat resisting thermoplastic resin (B) in the thermoplastic resin (A) does not exceed 20% by weight.
The method for reprocessing moldings according to the present invention relates to a method for reprocessing a molded article laminated with fabric which is made from a thermoplastic resin (A) and has a fabric, made up of fibers of a highly heat resisting thermoplastic resin (B), adhered to the surface thereof, wherein the method comprises charging an extruder with a crushed product obtained by finely crushing the molded article laminated with fabric, melt-blending the crushed product at a temperature, which is within the range of from the melting point to a temperature 50xc2x0 C. higher than the melting point of the highly heat resisting thermoplastic resin (B) constituting the fibers, to thereby produce a blend resin, and extruding the blend resin from the extruder to thereby granulate the blend resin.
Conditions suited for the implementation of the method for reprocessing a molding according to the present invention are as follow. The melt-blending temperature is within the range of from the melting point to a temperature 30xc2x0 C. higher than the melting point of the highly heat resisting resin constituting the fibers. The melt-blending time is 20 to 600 seconds. The thermoplastic resin (A) is a polyolefinic resin, such as high-density polyethylene or polypropylene, a polystyrene resin, an ABS resin, a modified polyphenylene ether, or the like. The thermoplastic resin (B) is nylon or polyester.
In the case of a crystalline thermoplastic resin, the melting point as referred to in the present invention is a melting point measured by differential scanning calorimetry. In the case of a noncrystalline thermoplastic resin, the melting point is referred to in the present invention as a flow-starting temperature (a temperature at which a flow of 2 mm3/second is attained under a condition using a load of 100 Kg and a die having a diameter of 1 mm and a length of 10 mm) when measured by means of a flow tester in which the resin flows down.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only a preferred embodiment of the invention is described, simply by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention.